MORGANTOWN, W.Va. (AP) -- Consol Energy Inc. has two plans to try to recover a bulldozer operator sucked into the Robinson Run slurry impoundment last week, the first involving a 40-foot pipe and a dive team from Louisiana.
Vice President for Safety Lou Barletta gave no time frame for the recovery operations in a media briefing Wednesday but said the first plan involves welding together two 20-foot pipes and lowering them vertically into the massive slurry pond near Lumberport where the dozer has settled.
Divers would enter the pipe through an access door, with an air supply and communications to operations based on barges on the surface, while water jets installed at the bottom of the pipe push away silt. The divers would work by touch in dark, murky water to try to locate the driver so he can be removed.
At the divers' request, Pennsylvania-based Consol has brought another dozer to the staging area so they can study it.
But Consol doesn't know the exact orientation of the dozer, Barletta said, or whether the operator is still in the cab.
Spokeswoman Lynn Seay said the victim's name is being withheld at the request of his family members, who are getting regular briefings on the recovery effort.
"We will wait until they feel ready and comfortable to share that information," she said.
The family was brought to the site Friday night, the same day as the accident that two other workers survived when their pickup trucks also went into the pond.
Though a section of the embankment failed, the federal Mine Safety and Health Administration said there was no risk to the public because the structural problems were inside, not outside, the impoundment.
The pond encompasses about 78 acres and is estimated to hold between 1.6 billion and 1.9 billion gallons of wastewater, the Department of Environmental Protection said. That's the equivalent of more than 2,500 Olympic-sized swimming pools, each of which holds about 600,000 gallons.
The impoundment is permitted to hold 3.4 billion gallons but typically operates well below that volume.
Slurry is a byproduct of washing coal to help it burn more cleanly.
Companies have disposed of the dirty water, silt and solids in various ways over the years, injecting it into worked-out underground mines, damming it in huge ponds like the one at Robinson Run and, less commonly, disposing of it with a dry filter-press process.
West Virginia has 114 coal slurry impoundments, according the MSHA. In all, there are 596 coal slurry impoundments in 21 states. Kentucky has the second-largest number with 104, while Illinois is third with 71.
Longwall mining operations at the Robinson Run mine were initially suspended after the accident, but Barletta said production resumed Wednesday. The preparation plant will also resume work soon, but the mined coal will be stockpiled until all safety precautions are in place, he said.
That involves erecting a boom across the pond with a curtain that descends about 4-5 feet into the water.
If the pipe dive to find the missing worker fails, Consol will resort to building what Barletta called a coffer dam. Sheet piling that weighs about 1 ton per section would be lowered into the pond around the dozer, walling it off.
Consol would then pump out silt but keep water inside the walled-off area to maintain a constant pressure on both sides. Divers would then be able to enter the water and search for the missing man.
The dozer is believed to be stuck 25-35 feet in the slurry, the silt and solids that settled beneath about 10-12 feet of dirty water.
Consol was working to raise the elevation of the impoundment when the accident happened, Barletta said, but the investigation into what went wrong only began Tuesday, so neither he nor regulators could comment on the possible cause.
The first goal is recovery, Barletta said. The second is to determine what happened "so we can learn from it and prevent similar incidents from occurring in the future."